Heretofore the procedure most frequently employed for the insertion of a large diameter catheter into a body vessel was the guide-wire technique of S. I. Seldinger which is described inter alia in Acta Radiology 39:368-376, 1953 and Br. Med. J. 2(6026):21-22,3 July 1976. Briefly, this procedure involves the execution of approximately ten carefully performed steps. First, the site area of skin is prepared and draped in the normal manner for percutaneous puncture. A local anesthetic is then administered as desired. Next, a small skin incision is made with a suitable scalpel. A thin wall puncture needle (stylette) of perhaps 16-18 gauge, surrounded by a small-bore cannula having an attached hub, is inserted through the skin into the vessel to be catheterized. Then the inner stylette is removed so that blood flows freely through the cannula and out the hub end. Next, the flexible end of a spring guide-wire is inserted through the cannula hub into the vessel. The cannula is then removed over the guide. Pressure is applied over the site of the puncture after the cannula is removed. A larger-bore "dummy" Teflon catheter and thin-walled sheath assembly is then inserted into the vessel over the spring guide. Next, the guide-wire and "dummy" catheter are grasped and removed together leaving the outer thin-walled sheath in the vessel. The diagnostic or therapeutic catheter is then fed through the sheath and into the vessel. Finally, the sheath is pulled out to the hub of the therapeutic catheter, or left in the vessel, as desired.
While the Seldinger technique has gained wide acceptance in the medical profession, a number of disadvantages are inherent in the procedure. The technique can be quite tedious even in the hands of the most experienced practitioner due to the required manipulation of the guide-wire and "dummy" catheter. Care must be taken not to withdraw the guide-wire into the cannula so as not to cause shearing of the guide. Intravascular knotting and separation of guide components have also been reported (Critical Care Medicine 9:347-348, April 1981). Vessel and organ perforation are other possible complications which one must be aware of when manipulating the guide-wire. It is also dangerous to advance the sheath and dilator together without a rotating motion, as otherwise the sheath may be damaged.